Roche immunotherapy shows response over range of cancers

May 15, 2013|Reuters

By Bill Berkrot

May 15 (Reuters) - An experimental Roche Holding AG drug that helps the immune system attack tumors was welltolerated and demonstrated an impressive effect against avariety of cancers, according to preliminary trial resultsreleased on Wednesday.

While clinical testing of the drug is still in its earlyphases, the Roche treatment is considered one of the mostpromising in a new class of immunotherapies being developed byglobal drugmakers.

The drug, called MPDL3280A, significantly shrank tumors in21 percent of 140 patients with advanced melanoma, lung canceror kidney cancer, according to data from a scientific abstractof the Phase I study. Of the 29 patients whose cancer respondedto the drug, 26 continued to respond - some more than a yearafter starting treatment - researchers said.

The study will be presented at the American Society ofClinical Oncology meeting in Chicago in early June.

Deutsche Bank analyst Tim Race, in a research note, saidwith this drug Roche "potentially has a greater than $5 billionproduct with potential for durable benefit across multiplecancers."

Roche's drug is an engineered antibody that targets aprotein called PD-L1 on cancerous tumors, a defense mechanismthat tumors use to trick the immune system's T cells intoremaining inactive. Once the T cells can recognize the cancer,they grow and multiply to more efficiently attack it.

"We have seen really amazing responses in lung cancer, inkidney cancer, in melanoma," Dr Roy Herbst, the study's leadinvestigator, said in an interview.

Broken down by cancer type, the response rate so far hasbeen 31 percent in melanoma, 22 percent in lung cancer and 13percent in kidney cancer, the available data showed.

The study has since been expanded to include patients withcolon, bladder and head and neck cancers, researchers said.

NO SERIOUS SIDE EFFECTS SEEN

MPDL3280A, which was administered intravenously every threeweeks, attacks a different target than a similar class of highlypromising immunotherapies called PD-1 inhibitors being developedby Bristol-Myers Squibb, Merck & Co and others.

Roche and some researchers believe the anti-PDL1 medicine ismore selective than the PD-1 drugs and may lead to lessinflammation of the lung and other organs.

The Roche drug was well tolerated in the study, Herbst said:There were no side effects that required limiting the dosing.

"Most of the adverse events were transient and of lowsignificance. We haven't seen any patients with significantinflammation of lung," said Herbst, chief of medical oncology atYale Cancer Center in New Haven, Connecticut.

The data on progression-free survival, or the average timebefore a cancer begins to worsen, was not yet complete, and itwill be a while before an overall survival benefit can bedetermined. But Herbst found the results thus far compelling.